The invention relates to a switch control device with silicone domes.
The main types of switch systems currently used in the automotive field can be summarized as follows:                switches with quick-snap metal foils;        switches with silicone bubbles and on-board contact;        switches with silicone bubbles and metal contact integral with the electronic circuit;        switches with snap-type metal domes that can be actuated either directly or via a silicone intermediary.        external switch actuated by means of an actuating means and silicone domes.        
These different types of operating principles have definite intrinsic characteristics both mechanically, e.g. forces, travels and noise, and electrically, such that in some cases they cannot meet the new requirements of the automotive world.
In particular, the use of external monolithic switches for opening and closing electric circuits introduces an uncertain variable into the determination of the contact or switching point of the switch itself.
Moreover, external switches have intrinsic mechanical characteristics that must be duly taken into account in order to obtain the feeling characteristics required in the automotive field.
For the purposes of the present invention, the term “external switch” refers to a monolithic solid-state switch comprising an outer casing and a push-button, which is electrically connected to a printed circuit board. The control device acts upon said external switch.
For the purposes of the present invention, the term “feeling” refers to the force and displacement perceived by the user as he/she operates a key of a push-button that includes a switch.
Switch control devices are known, such as, for example, the one described in patent application ITTO20100636 by Bitron, wherein, for closing a switch, e.g. comprising conductive elements or silicone domes, the control device comprises a metal foil adapted to create an elastic lever to modify the force/displacement response of the device with respect to the intrinsic characteristic of a silicone dome, for the purpose of accelerating the response of the switch and ensure the proper commutation of the switch.
The solution described in the above-mentioned patent is difficult to implement for actuating an external switch.